1. Field of the Invention
The present invention relates to gastrointestinal feeding system, and more particularly to low profile gastrostomy devices having an inflatable balloon member. More specifically, the present invention relates to a low profile gastrostomy device having an indicator for indicating the inflationary state of the balloon member.
2. Prior Art
Low profile gastrointestinal feeding systems are frequently used for patients who are unable to take nutrition orally and require some type of gastrostomy device to provide nutrition through the gastrointestinal tract, such as the stomach. These gastrointestinal systems usually comprise a conventional feeding set of tubing attached to a source of nutrition at one end and a low profile gastrostomy device at the other end. The low profile gastrostomy device comprises an external retention member having a hollow tubular member extending axially therefrom with an inflatable balloon member attached to the tubular member. The tubular member provides a fluid pathway from the feeding set directly to the patient's gastrointestinal tract. The low profile gastrostomy device is normally inserted through a stoma formed through the patient's abdominal and stomach walls such that the balloon member enters the patient's gastrointestinal tract in a deflated condition and may be retained therein by placing the balloon member in an inflated condition and anchoring it against the wall of the gastrointestinal tract. Specifically, the balloon member is provided along a portion of the tubular member to hold and affix a portion of the gastrointestinal tract, i.e. the stomach, against the posterior abdominal wall of the patient when the balloon member is placed in the inflated condition. The stomach is so affixed by capturing the organ wall and abdominal wall between the inflated balloon member secured inside the organ and the external retention member seated on the outer abdominal wall of the patient.
As noted above, to anchor the low profile gastrostomy device after deployment inside the patient, the inflatable balloon member is placed in the inflated condition by a user which prevents it from being withdrawn through the stoma of the patient. Once the low profile gastrostomy device is so deployed, it is often desirable for the user to have some indication as to the inflationary state of the inflatable balloon, especially if a leak develops or fluid is inadvertently evacuated. U.S. Pat. No. 4,592,747 to Pool discloses a flow sensor having a body that defines a recessed surface covered by a flexible cover for medical dispensing systems. The flexible cover is movable between a contracted position wherein the cover contacts the recessed surface in response to changes in fluid flow through an internal passage. Although the Pool device provides an indication of fluid flow through a conduit, the flow sensor does not give a clear visual indication as to the inflatable condition of a flexible membrane, such as a balloon. Moreover, the cover of the flow sensor is not integral and must be securely engaged to the flow sensor body in order to ensure proper operation.
Similarly, U.S. Pat. No. 4,398,542 to Cunningham et al. discloses a fluid pressure measurement device comprising a body having an opening through an exterior surface into the channel with a separate flexible membrane covering the opening which is sealed to the body. The flexible membrane is also movable to an expanded position in response to a positive pressure being carried by IV tubes. However, similar to the Pool device, the flexible membrane is not integral and may be difficult to view properly in the dark or dim lighting conditions.
Other devices such as U.S. Pat. No. 4,872,483 to Shah and U.S. Pat. No. 5,218,970 to Turnball et al. employ electronic devices for indicating the inflationary state of a flexible balloon member, such as a pressure cuff monitor or electronic manometer. Unfortunately, these electronic devices are expensive to manufacture and require mechanical assemblies to provide a visual indication of inflationary state. Unfortunately, prior art gastrostomy devices do not have simple and inexpensive means for visually and tactilely indicating the inflationary state of a balloon member.
Therefore, there appears a need in the art for an integral external inflationary indicator for a low profile gastrostomy device that provides a continuous visual and tactile indication relating to the inflationary state of the balloon member.